Is a well-estabished community language an obstacle to second language learning?

I have heard some people say that the people in Japan, Korea and Taiwan are not as good in English as those in Thailand, Malaysia, Philippines, etc. because the national languages of the former are too well-established and don't allow room for English. It's obvious this theory doesn't stand. What about Sweden, the Netherlands, etc. where the "national" languages are well-established and standardized, but people are phenomenal in English? What about Thailand? I think Thai people are as proud of their wonderful language as the Taiwanese are about Mandarin, and as insistent in using it to communicate with any foreigner who even has a tiniest bit knowledge of it, and yet do quite well in English? Conversely, what about Malaysia, which had once succeeded in codifying its national languages and even made it the sole medium of instruction in tertiary education in the 1980s, but then turned back to English afterwards?

But it is useful to know that for the majorities of people around the world, their "mother tongue" is not the same as the one that's taught in schools. Cases like Japan and Korea, where most people speak the same language at home and school and work and everywhere else, are really rare. It is a highly artificial situation, influenced by the nation-state ideology originated from Europe, i.e. France. It took many years and much effort on the part of the government of Japan, for example, to eliminate all "dialects" to arrive at the perceived "monolingual" state of today. In many countries, there are many languages that are spoken but not standardized enough to be used as a medium of instruction at school. It is expensive to develop those languages and compile textbooks in them. And most of those countries are poor. So the teaching has to be continued in their former colonial language, usually English, French or Portuguese, because materials are more readily available. (The situation in most former Spanish colonies is a bit different, because Spanish has already become the native language of the majority of people.) This creates many problems, of course. One is that it unfairly advantages rich people in urban areas, who have more access to English. (Or French for that matter.) And studies overwhelmingly show that people learn better when they are taught in the language they speak at home, or the one that's widely spoken in the community.

That leaves us with the discussion of the countries that have chosen one of the local languages as the national language. These countries can be classified into two types, I think. The type one are those which have already successfully developed and propagated that language, so much so that other languages originally used are dying out. The other are those which have taken more laissez-faire approach. Thailand is one example of the former. The government has standardized the language and developed enough vocabulary, so almost everything can be done in midland Thai. Many non-Thai speaking peoples first became bilingual in their own language and Thai, and then the young generation grew up knowing only Thai. Politically, Thai was propagated as the symbol national unity. So people started to feel very proud about this language. Minority languages became more marginalized, or even died out.

An example of the latter is the Philippines. Even though the constitution says English and Filipino are official languages, and bilingual elementary education in a local language and Filipino are propagated, it's largely up to each individual to choose which language to do what. As a result, a child from a upper middle-class Manila family may grow up speaking English or "Taglish" as his home, school and community language, all at the same time. On the other hand, another child from a remote area might speak his mother tongue at home, a regional lingua franca like Cebuano to be his community language, Filipino and English as his school languages. Obviously, under normal circumstances, it is so much harder for the second child to do well at school. Nowadays, because of the influence of the electronic media, Tagalog seems to be the winner in this laissez-faire competition. Even people from very remote places can now speak at least some Tagalog. Overseas Filipino Workers who have different first languages also seem to use Tagalog as the lingua franca once away from home.

Now which one is Taiwan, anyway? I think Taiwan was on the way to Type 1, then turned Type 2, but it's too late. During the authoritarian era, the government tried to eliminate "dialects" and promote Mandarin. The high-handed method of giving "dog tags" for those who didn't conform to this rule is notorious. When Taiwan was democratized, it moved on to a more laissez-faire style, with a renaissance of non-Mandarin languages, especially Hokkien and Hakka. But I think it's a bit too late. Very few of my students can converse fluently in Hokkien. Quite a few of them don't understand any at all, even if they are ethnically Hokkien. It's paradoxical, because those are the guys who went to elementary schools when "Mother Tongue" was already a compulsory subject. Hokkien might go down the way of the Irish language in Ireland. Significant things can be said only in English there.

I want to talk more about medium of instruction issue. I hope I'll get to doing it soon.